Will BIM Make CAD Irrelevant? At Larson & Darby, the Answer Is 'No'

A transition to Autodesk Revit doesn't need to be an all-or-nothing proposition. Day to day, AutoCAD still gets the job done eloquently.

Editors' Note: Through a sponsorship by Autodesk, Cadalyst editors bring you this feature, part of a special series of articles that highlight the role of AutoCAD and 2D design in today's demanding CAD work flows. You can watch for the next installment in February.

Building information modeling (BIM) seemingly is ubiquitous in design firms today. Large, medium, and small firms are using it. Clients increasingly are asking for it. There's no doubt that its rendering and integration capabilities are unsurpassed, and its life-cycle planning potential as of yet isn't fully realized. So, then, with all that power, should we assume that traditional 2D programs such as AutoCAD eventually will go the way of the dodo? Gedeon (Ged) Trias, Assoc. AIA, Associate Director of Design with the Larson & Darby Group in Rockford, Illinois, firmly believes that answer is no. Although the architecture, engineering, and interiors firm has rolled out Autodesk Revit and successfully completed numerous BIM projects using that software, Larson & Darby still chooses to perform the bulk of its work in AutoCAD.

Larson & Darby was one of the first firms in its region to integrate AutoCAD into its daily work flow, and during the past twenty-odd years, the firm has produced the majority of its projects using AutoCAD. The firm typically installs every other version of AutoCAD and currently is using 2010, although it does have a few seats of 2011 to afford designers the opportunity to try out some new and updated features, such as the text editing, transparency, and constraint tools.

Although Larson & Darby has started to use Revit in project work flow, AutoCAD remains its choice for a lot of its design work. Here, an overall shot of a project lets the designers quickly show clients how the proposed design integrates with their building. (Image courtesy of Larson & Darby.)

The ability to bring all its legacy information forward through each AutoCAD update is an invaluable asset for a firm that has a many long-term and repeat clients. "DWG is still the gold standard for our industry, at least as far as I'm concerned, so the fact that we could pull up those old projects and work on them today, we wouldn't know what we would do without that capability," said Trias.

Choosing to Have It Both Ways

The decision as to whether to execute a project in AutoCAD or Revit depends on several factors at Larson & Darby. Most small projects, and those that rely on legacy information, still are executed in AutoCAD, while many large projects begin in AutoCAD and then move to Revit. For example, the firm recently completed an addition to the University of Illinois College of Medicine at Rockford using AutoCAD. The choice to complete the College of Medicine in AutoCAD was driven primarily by its history. The project began in the mid-1990s and was in development for a long time, predating the firm's Revit implementation. Trias believes that changing platforms midstream wouldn't have been cost effective or beneficial to the client.

The firm also just finished a bus terminal project that was started in AutoCAD but completed in Revit. The bus terminal was unique because of the complex forms of the project, explained Trias. "The updating and refinement of the complex architecture made the 3D approach that Revit offered an easy decision," he said.

"We've got this established work flow for utilizing [Auto]CAD and, though some of our designers are using Revit as the base point for that work flow, [most] will start in [Auto]CAD as a 2D plan exercise," Trias explained. "Then, depending on how the project goes, [they] will either move it through [Auto]CAD entirely or we might move it over into Revit or something like that and use [AutoCAD] as a documentation tool."

The reasons for choosing AutoCAD or Revit vary by project. Sometimes it's determined by availability; other times by schedule or need. "We currently have more trained AutoCAD users in our office than we have trained Revit users, so the choice becomes obvious," explained Trias. "[Additionally,] the timelines we have for some of our projects don't make it cost effective for the front end that Revit can require, but that may be a work flow or even a perception issue based on where we are in our Revit implementation. This may change as our Revit user base expands."

Even before Revit, 3D modeling was an important part of the firm's design work flow. The precision and speed of 3D modeling was essential in communicating to project teams how the structure of this addition was going to work. (Image courtesy of Larson & Darby.)

Trias also noted that particular elements of a project likewise can lead to the decision to use both software programs. "We've had projects where Revit was used for the conceptual and design development portion," he continued, "but due to timeline and personnel availability, we've ported the project out to AutoCAD for construction documents. We've also had other projects like the bus terminal that conceptual design and design development were done in AutoCAD and then brought into Revit for the coordination power that Revit brought to the table. More recently we've seen a few projects require a BIM platform as part of the deliverables, making our decision for us."

Although the firm is increasing its use of Revit as it completes the roll out to the firm's engineers, Trias doesn't envision a time when Revit will completely replace AutoCAD. Instead, he believes that using Revit for all projects would be akin to using a crowbar to open a beer bottle: overkill. Trias expects AutoCAD will continue to evolve and remain extremely useful, and he credits Autodesk with keeping a finger on the pulse of what architects want in a design program and being quick to implement those features and tools.

"There has been an evolution to [AutoCAD] in terms of being able to grow with the requirements — things like the 3D capabilities that have gotten progressively better over the years — and even their improvements in rendering technology within the program itself," said Trias. "They've got the mental ray engine in there so you can do some pretty amazing renderings within the software itself without having to go out to other products. We still use those other products, but the fact that those things are all in one place is pretty amazing, and we've used that a number of times over the years."

Improving Functionality

Whereas pre-2008 AutoCAD lacked solid 3D rendering capabilities that could compete with BIM-specific products, more recent versions have improved the functionality considerably. In 2010, AutoCAD introduced parametric functionality and mesh modeling, and the 2011 version can convert point cloud data into useful geometry. AutoCAD 2011 also offers enhanced user interface features such as a new pull-down menu on the Quick Access Toolbar (QAT), which now includes the Save and SaveAs commands, and a new Hatch ribbon tab. For Larson & Darby, Trias reported that the new Surface tab with three new surface types is a huge improvement over earlier versions as they bring a level of flexibility and control over modeling surface types and methods that were available only in other products or through a lot of work within AutoCAD. Trias added, "They work within the familiar AutoCAD command environment, so even a new user can quickly add these new tools it to their work flow. Forms that I might have had serious concerns about attempting within AutoCAD are much, much easier now."

When the finished work looks like the rendering, it's always a good sign. Larson & Darby's exhibit hall addition to the Midway Village Museum Center was completed in 2010 and dramatically improves the appearance of an important cultural landmark. (Image courtesy of Larson & Darby Group.)

"We're also a big fan of the Autodesk Impression software package," added Trias, referring to the product (available to AutoCAD subscription customers) that gives a hand-rendered look to DWG and DWF drawings. "It takes [Auto]CAD work and gives it another dimension as far as allowing you to do more artistic presentation drawings and things like that. We've been using that for a long time and have found our clients really react to it well. It takes the hard edge away from drawings and lets people view those drawings as a more a work in progress in a way that [Auto]CAD sometimes does not."

These Impression renderings show different styles on a similar floor plan, giving clients options for a medical building. The sketch quality kept the design intent clear to gauge client reaction while still giving Larson & Darby ample latitude to refine the design. (Image courtesy of Larson & Darby Group.)

Trias believes that, by far, AutoCAD's greatest asset is its customizability. He elaborated, "Our firm has had the benefit of some stellar power users that have crafted LISP routines that are an integral part of our CAD work flow, even today. As far as user interface customizability goes, we all know that no two AutoCAD users are the same, and the ability to fine-tune the interface to allow each individual user to get to where they want to go as quickly as possible is equally important. I learned AutoCAD on version 2.62, so how I might want to perform a task could be different from a relatively new user, and yet we can still both sit in front of the most current version and get exactly what we want done. To me that kind of operational legacy is amazing."

At Larson & Darby, AutoCAD touches nearly every project that goes out the door in one way, shape, or form, and although it has embraced BIM and is integrating it into every aspect of its practice, Larson & Darby will continue to rely heavily on the functionality provided by AutoCAD. As Ged Trias said, "We wouldn't be able to do what we do without the AutoCAD tool set."

About the Author: Heather Livingston

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